Sorry, I just read the post above explaining what the copper coil does. That being said, are you recommending more power? If so, how much. I have the sub enclosure (.88 cu.ft.) and I'm trying to set up a sub/amp that will work with the given volume. I haven't decided on an amp yet. I looked at a Planet Audio RXD1000, a class D which produces 750w RMS @2 ohm. They have larger units available. Thoughts?